A variety of roll-over fuel valves are known, also such combined with other functions.
For example, U.S. Pat. No. 5,738,132 discloses a roll over vent valve comprising: a housing having a fluid inlet and a fluid outlet, the latter comprising a substantially elongated slit-like outlet aperture of the housing bounded by a valve seating. There is furthermore provided a float member located in the housing and axially displaceable within the housing between the inlet and the outlet; an elongated flexible closure membrane strip anchored at one end thereof to an end of the float member adjacent the outlet and at a portion thereof offset with respect to the outlet; spring biasing means located within the housing and bearing on the float member so as to spring bias it in the direction of the outlet; whereby the spring biasing together with buoyancy forces acting on the float member tend to press the membrane strip into sealing engagement with the outlet aperture whilst gravity forces acting on the float member tend to displace the float member away from the outlet so as to progressively detach the strip from sealing engagement with the outlet.
U.S. Pat. No. 8,109,285 is directed to a roll-over vent valve, comprising: a housing formed with a fluid inlet and a fluid outlet, a valve seating bounding an outlet aperture of the housing, a float member comprising a sealing member, the float member received within the housing and axially displaceable between a sealed position wherein the sealing member sealingly bears against the valve seating of the outlet aperture to seal the fluid outlet, and an open position wherein the sealing member is disengaged from the valve seating whereby the fluid outlet is in flow communication with the fluid inlet; a pressure-retention device extending intermediate the valve seating and the fluid outlet, to thereby shut fluid flow therebetween as long as pressure differential between the fluid inlet and the fluid outlet does not exceed a minimal pressure threshold; and a one-way fluid inlet valve being in flow communication with said fluid outlet to allow fluid flow towards the fluid inlet at a substantially high flow rate in the event of under-pressure at the fluid inlet, the one-way fluid inlet valve comprising a cage having an inlet port provided through a wall portion of the housing and being in flow communication with the fluid outlet of the roll-over vent valve, and an outlet port provided through a cage closure fixed to the housing and being in flow communication with the fluid inlet of the roll-over vent valve, wherein the cage closure and the wall portion define therebetween a gap in which a sealing member is freely retained thereby being displaceable and deformable within the gap between sealing engagement of the inlet port and disengagement therefrom.
It is an object of the presently disclosed subject matter to provide a roll-over valve (ROV) integrated with an over-pressure relief valve (OPR) and a pressure retention valve (PRV).